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Visa fullständig version : HIIT omvandlar långsamma muskelfibrer till snabba


King Grub
2018-05-30, 12:28
90 intervaller på 250 % av max låter dock inte så roligt.

We present here a longitudinal study determining the effects of two 3 week-periods of high intensity high volume interval training (HIHVT) (90 intervals of 6 s cycling at 250% maximum power, Pmax/24 s) on a cycle ergometer. HIHVT was evaluated by comparing performance tests before and after the entire training (baseline, BSL, and endpoint, END) and between the two training sets (intermediate, INT). The mRNA expression levels of myosin heavy chain (MHC) isoforms and markers of energy metabolism were analyzed in M. vastus lateralis biopsies by quantitative real-time PCR. In incremental tests peak power (Ppeak) was increased, whereas V˙O2peak was unaltered. Prolonged time-to-exhaustion was found in endurance tests with 65 and 80% Pmax at INT and END. No changes in blood levels of lipid metabolites were detected. Training-induced decreases of hematocrit indicate hypervolemia. A shift from slow MHCI/β to fast MHCIIa mRNA expression occurred after the first and second training set. The mRNA expression of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), a master regulator of oxidative energy metabolism, decreased after the second training set. In agreement, a significant decrease was also found for citrate synthase mRNA after the second training set, indicating reduced oxidative capacity. However, mRNA expression levels of glycolytic marker enzyme glyceraldehyde-3-phosphate dehydrogenase did not change after the first and second training set. HIHVT induced a nearly complete slow-to-fast fiber type transformation on the mRNA level, which, however, cannot account for the improvements of performance parameters. The latter might be explained by the well-known effects of hypervolemia on exercise performance.

High Intensity High Volume Interval Training Improves Endurance Performance and Induces a Nearly Complete Slow-to-Fast Fiber Transformation on the mRNA Level. Front. Physiol., 29 May 2018.

https://www.frontiersin.org/articles/10.3389/fphys.2018.00601/full

svenbanan
2018-05-30, 13:11
90 intervaller på 250 % av max låter dock inte så roligt.



High Intensity High Volume Interval Training Improves Endurance Performance and Induces a Nearly Complete Slow-to-Fast Fiber Transformation on the mRNA Level. Front. Physiol., 29 May 2018.

https://www.frontiersin.org/articles/10.3389/fphys.2018.00601/full

Nu hänger ju inte jag med i svängarna, men jag tycker mig känna igen att det sedan länge varit känt att man kan omvanda snabba fibrer till långsamma genom att typ nöta långdistanslöpning i sakta mak. Däremot har man väl inte varit säker på att man kunnat reversera processen. Så detta borde vara hyfsat revolutionerande, eller?

Men vad betyder 250% Pmax egentligen? Hur kan man komma över 100% power?

90 intervaller låter som en mardröm... *spy*

Termy
2018-05-30, 13:23
Man fick ju i alla fall 24 sekunders vila mellan varje mardröm. Tid nog att hinna reflektera över livet, innan det passerar i revy...

Bob90
2018-05-30, 13:32
Nu hänger ju inte jag med i svängarna, men jag tycker mig känna igen att det sedan länge varit känt att man kan omvanda snabba fibrer till långsamma genom att typ nöta långdistanslöpning i sakta mak. Däremot har man väl inte varit säker på att man kunnat reversera processen. Så detta borde vara hyfsat revolutionerande, eller?


+1 :confused: